An integrated circuit (“IC”) die may be assembled into an IC package by physically and electrically coupling it to a substrate made of organic or ceramic material. One or more IC packages may be physically and electrically coupled to a printed circuit board (“PCB”) to form an “electronic assembly”. The “electronic assembly” may be part of an “electronic system”. An “electronic system” is broadly defined herein as any product comprising an “electronic assembly”. Examples of electronic systems include computers (e.g., server, router, desktop, laptop, hand-held, Web appliance, etc.), wireless communications devices (e.g., cellular phone, cordless phone, pager, etc.), computer-related peripherals (e.g., printer, scanner, monitor, etc.), entertainment devices (e.g., television, radio, stereo, tape and compact disc players, video cassette recorder, camcorder, digital camera, MP3 (Motion Picture Experts Group, Audio Layer 3) player, etc.), and the like.
An IC die may comprise one or more active and/or passive circuits. At least one surface of the die may comprise a number of pads or contacts to couple the die functionally to another element, such as an IC substrate. To operate at relatively high clock frequencies, some dice may contain dielectric material having a relatively low dielectric constant (“K”), for example, less than 3.6. Such dielectric materials may be structurally relatively weak and may have relatively low fracture toughness.
An IC substrate may comprise a number of layers. Some layers may comprise organic or ceramic dielectric material. Some layers may comprise conductors, such as traces, ground planes, and vias. An IC substrate may include an electronic component mounted on a surface of the substrate. The electronic component may be functionally connected to other elements of an electronic system through a hierarchy of conductors that include the substrate traces, ground planes, and vias. The conductors may carry signals that are transmitted among the electronic components, such as IC's, of the system. An IC substrate may have a relatively large number of input/output (“I/O”) terminals (also called “lands”), as well as a large number of power and ground terminals or lands, on a surface of the IC substrate.
In the field of electronics there is competitive pressure among manufacturers to drive the performance of their equipment up while driving down production costs and maintaining acceptable yield and reliability. This is particularly true regarding the packaging of dice on substrates, where each new generation of packaging must provide increased performance, particularly in terms of higher clock frequencies, while generally being smaller or more compact in size.
In known IC packages in which the contacts of a die having one or more low-K dielectric layers are electrically and mechanically coupled to corresponding lands of an IC substrate, the yield and reliability may diminish to unacceptable levels.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding this disclosure, there is a significant need in the art for apparatus and methods for packaging a die on a substrate that minimize yield and reliability problems associated with dice containing low-K dielectric materials.